4 replies to this topic

[samydong]

hi ，everyone
I'm a newbie on experiment. I'm trying to test some small-molecule inhibitor for the enzymes in vitro to get the IC50. I have no idea about how to design the experiments, such as concentration,  dose. So please let me know if anyone has any suggestion?
  Please help me with this....
Thanks.
Dong

[bob1]

Concentration and dose are more or less the same thing, though dose often has a time component to it.  The range you should use is dependent on the compund you are using, so further details would be necessary before we can tell you what is best to use.  These are questions that you should be discussing with your supervisor too - they will be able to give you some guidance on appropriate ranges and solvents etc.

Have a look here and the references therein for a basic description and experimental design.

[drwho]

IC50 is a product of a curve so you need to make sure your curve is good.  So this mean you need to have enough points on your curve to make it a good fit (if you do not understand what I mean by this you need to understand the mathematics of curves)  I would never use less than 7 points.  To clarify what I mean by 7 points is 7 doses of your drug.  These really should be log doses as show in the link in the above post.

What you need is the top and the bottom of your curve if you can not find these your IC50 will not mean anything.

Edited by drwho, 27 September 2012 - 01:44 PM.

[samydong]

bob1, on 25 September 2012 - 03:23 PM, said:

Concentration and dose are more or less the same thing, though dose often has a time component to it.  The range you should use is dependent on the compund you are using, so further details would be necessary before we can tell you what is best to use.  These are questions that you should be discussing with your supervisor too - they will be able to give you some guidance on appropriate ranges and solvents etc.

Have a look here and the references therein for a basic description and experimental design.

Thank you very much for your help.

[samydong]

drwho, on 27 September 2012 - 01:32 PM, said:

IC50 is a product of a curve so you need to make sure your curve is good.  So this mean you need to have enough points on your curve to make it a good fit (if you do not understand what I mean by this you need to understand the mathematics of curves)  I would never use less than 7 points.  To clarify what I mean by 7 points is 7 doses of your drug.  These really should be log doses as show in the link in the above post.

What you need is the top and the bottom of your curve if you can not find these your IC50 will not mean anything.

Thank you for your suggestion.